Purpose: This study examined if past exercise habits moderated the mediational influence of intention to exercise on the relationship between exercise identity and exercise behavior. Methods: Physically active university students (N=565) responded to a past behavior, exercise ientity, intention, and the Godin leisure-time exercise questionnaire. Moderated mediation was tested using a SPSS moderated mediation macro (Preacher, Rucker, & Hayes, 2007). Results: Multiple regression analysis showed that all criteria for mediation were met. Furthermore, the relationship between exercise identity and exercise behavior was moderated by past exercise behavior(β=.08, p<.05). Conclusion: Findings confirm the importance individual's past exercise habits and exercise identity support the extended Theory of Planned Behavior by showing significant moderation by past exercise behavior. Results demonstrates the importance of moderated mediation models to determine complex interaction between psychological constructs and exercise behavior.